1. Field of the Invention
This invention relates to a photographic camera, and more particularly to a 35 mm camera for use with a 35 mm film cassette having a cylindrical cassette body.
2. Description of the Prior Art
The 35 mm film cassettes most widely used at present generally comprise a hollow cylindrical cassette body having an integral tongue portion extending tangentially from the side surface thereof. A film spool is mounted for free rotation along the longitudinal axis of the cassette body and the film is wound therearound. An exit slit is formed in the tongue portion and the film leader is projected outside the body through the exit slit.
When loading a conventional camera with such a film cassette, the backlid of the camera is first opened widely and the cassette is inserted into the film chamber with its upper and lower ends correctly positioned therein so that the film spool engages with the rewind cam projecting into the chamber. Then the film is drawn out from the cassette body across the film aperture and the tip of the film leader is inserted into a slit in the film take-up spool while the perforations of the film are brought into engagement with the transport sprockets. Thereafter, the film wind-up lever and the shutter release button are carefully operated to correctly wind the film around the take-up spool. When it is confirmed that the film is correctly wound, then the backlid is closed. This conventional film loading operation is rather troublesome and requires a certain amount of skill. Accordingly the film loading operation is rather difficult especially for the aged, women or children.
There have been proposed various types of cameras improved to make the film loading operation easier. However, even in these improved cameras, the film loading operation cannot be accomplished by simply inserting the film cassette into the film chamber. In other words, other operations are still required in addition to insertion of the film cassette. For example, in a certain type of improved camera it is necessary to draw out the film from the cassette body and to position the film leader near a film take-up chamber. In another type the film must be pressed down until the backlid is closed to keep it from curling up as is its natural tendency. In still another type having a specially designed film take-up chamber, it is necessary to insert the film leader into a slit formed in the film take-up chamber.
There also have been known 110 cartridges and 126 cartridges having a film feeding chamber and a film take-up chamber formed integrally. These cartridges can be easily loaded into a 110 camera or a 126 camera. However 110 cameras and 126 cameras are not in wide use. Further, the 35 mm film cassette and the 110 or 126 cartridge differ from each other in their systems. Therefore, the concept of the 110 or 126 cartridge cannot be applied to the 35 mm cassette.
In our Japanese Patent Application No. 55(1980)-186574, we have proposed a 35 mm camera which can be easily loaded with a conventional 35 mm film cassette by simple insertion of the cassette, without need to touch or manipulate the film leader thereof. The camera has an openable backlid member and a film chamber member defining a cassette receiving chamber. The cassette receiving chamber is exposed when the backlid member is opened and comprises a cylindrical portion and a slot portion which substantially conform with the cylindrical body and the tongue portion in shape. Thus the cassette receiving chamber determines the position of the film cassette when it is inserted thereinto and holds the film cassette in place. A guide member extends from the film chamber member to define between the inner surface of the backlid member and itself a film guiding slit aligned with said slot and extending beyond the film aperture of the camera body. The guide member has an inclined surface inclining downward toward the backlid member. When the cassette is inserted into the cassette receiving chamber, the lower edge of the leader abuts against the inclined surface to be stretched and smoothly introduced into the film guiding slit.
However this camera is disadvantageous in that it is difficult to automatically bring the leader into engagement with the film wind-up mechanism if the length of the leader projecting from the cassette body is too long and the leader extends beyond the side edge of the backlid member. In such a case, the leader must be manually cut.